Why most charitable deductions quietly died in 2018
The math that used to work — every donated dollar reduces taxable income — now has a gate in front of it. Deductions only matter above the standard deduction ($15,000 single / $30,000 joint for 2025), and with state and local taxes capped at $10,000, a typical married couple's itemizables (capped SALT + shrinking mortgage interest) sit a few thousand dollars below the bar. Their $8,000 of annual giving pushes the total barely past standard — so only the sliver above $30,000 does any tax work, and often none does. Roughly 90% of filers now take the standard deduction, which means most charity in America earns no deduction at all. Bunching is the legal, boring fix: since the standard deduction resets every year, alternating between one giant itemized year and standard-deduction years harvests both.
The mechanics, in one example
A joint filer with $10,000 of capped SALT, $9,000 of mortgage interest and $8,000/year of giving. Every-year strategy: itemizables total $27,000 — below $30,000, so they take the standard deduction both years: $60,000 of two-year deductions, zero benefit from $16,000 donated. Bunched: give $16,000 in January and December of year one → $35,000 itemized in year one, $30,000 standard in year two = $65,000 of deductions. Same charities, same dollars, $5,000 more deducted — $1,200 back at a 24% marginal rate, every cycle, forever. Three-year bunching stretches the gap wider for smaller givers; the calculator flags when that's your version.
The donor-advised fund: bunching without lumpy charities
The objection — "my church needs monthly support, not a lump every two years" — is exactly what a donor-advised fund (DAF) solves. Contribute the bunched amount to the DAF in the tax year (deduction locks in immediately), then grant it out to charities on any schedule you like — monthly for years, if that's your pattern. Fidelity, Schwab and Vanguard run them with low minimums and near-zero friction. The DAF also unlocks the strategy's power move: donating appreciated stock instead of cash. Give shares held over a year and you deduct the full market value and nobody ever pays the capital-gains tax embedded in them — a double benefit worth more than the bunching itself for anyone holding big winners in a taxable account (the capital gains calculator shows what's being erased). Sell-then-donate is strictly worse than donate-then-let-the-charity-sell; the DAF makes the clean version one form.
Timing partners: what else belongs in the fat year
Bunching composes with everything else that moves taxable income between years:
- High-income years are bunching years. A big bonus, RSU vests, a business exit — deductions are worth the most against your highest marginal rate, so aim the itemized year at the income spike.
- Roth conversion years are usually NOT bunching years — conversions are deliberately done in low-rate years (the conversion math), where deductions are worth least. Separate the two.
- From 70½, QCDs beat bunching entirely for IRA owners: qualified charitable distributions satisfy RMDs without touching taxable income — no itemizing needed, better than any deduction. Bunching is the accumulator's tool; QCDs are the retiree's.
- Medical procedures (deductible above 7.5% of AGI) and even January's mortgage payment (13 payments of interest in one year) can pile into the same fat year at the margin.
When not to bother
If your base deductions already clear the standard bar every year (big mortgage in a high-tax state), every donated dollar already deducts fully — bunching adds nothing but complexity. If giving is small relative to the gap (a $1,000/year giver rarely moves the needle even bunched), take the standard deduction and give anyway — the tax tail should never wag the generosity dog. The strategy's sweet spot: households giving $5,000-25,000 a year whose other itemizables hover near the standard deduction — for them, a calendar change is worth $1,000-4,000 per cycle, indefinitely, at zero cost to the causes they fund. Check where the freed-up money does the most good next with the tax bracket calculator.